no experience using sky, but I have done a lot of wilderness hiking. Two critical things are topo map and a compass. you need both. a map is near useless unless you have a compass so you can orient the map to north. otherwise you have no idea what direction you are going. Of course on highways it is easier but still the map and compass (and knowing how to uset them) are very helpfull. I also think a hand held gps is nice and i usually have all three when hiking. If you know how to use them you have to work to get lost.

One other thing. If you have a map and compass you can orient the map and then use the compass and sightings off of terrain features to triangulate your exact position on the map. That makes it a lot easier to navigate when you actually know where you are. There are books that tell you how to do all of this. Small books. You can buy one from the Boy Scouts store.